The present invention relates to an apparatus for holding synchronizer keys in a synchronizer provided in a transmission for a motor vehicle, in order to prevent the keys from disengaging from the synchronizer.
In a change-speed power transmission having odd speeds, one of synchronizers must be provided for only one speed gear. Accordingly, no synchronizer ring and gears are provided on one of sides of the synchronizer to form an inoperative side. However, the sleeve of the synchronizer may be shifted to the inoperative side, for example, in order to select a reverse gear. When the sleeve is shifted in the direction, synchronizer keys may disengage from the synchronizer. To eliminate such a failure, a plate is attached to the synchronizer for holding the keys.
Japanese Utility Model Laid Open 57-40729 discloses a device, in which a retainer is secured to a boss formed on a synchronizer hub so as to prevent the disengagement of keys. However, the retainer is complicated in shape and the synchronizer hub must be formed in different shape from the ordinary synchronizer. Further, the retainer must be independently attached irrespective of the assembling of the synchronizer, which means complification of the attachment of the retainer.